Fluid-cooled led-based lighting methods and apparatus for controlled agricultural environments

ABSTRACT

A lighting fixture has an extruded aluminum housing, at least one light source mechanically supported by the extruded aluminum housing, and at least one copper pipe thermally coupled to the extruded aluminum housing to carry a fluid coolant. During operation of the lighting fixture, the fluid coolant flowing through the at least one copper pipe extracts heat generated by the lighting fixture, and the fluid coolant does not contact the extruded aluminum housing. In one example, a copper fluid coolant circuit is thermally coupled to the housing to contain the fluid coolant, and the lighting fixture does not contain any internal seals or internal O-rings for the fluid coolant.

CROSS-REFERENCE TO RELATED PATENT APPLICATION(S)

This application is a continuation of, and claims priority to, U.S.application Ser. No. 17/141,173, filed on Jan. 4, 2021, entitled“FLUID-COOLED LED-BASED LIGHTING METHODS AND APPARATUS FOR CONTROLLEDAGRICULTURAL ENVIRONMENTS HAVING A VERTICALLY-STACKED MULTIPLE-LEVELGROWING AREA,” which, in turn, is a continuation of, and claims priorityto, U.S. application Ser. No. 16/114,088, filed on Aug. 27, 2018,entitled “FLUID-COOLED LED-BASED LIGHTING METHODS AND APPARATUS FORCONTROLLED ENVIRONMENT AGRICULTURE,” which, in turn, claims a prioritybenefit to U.S. Provisional Application Ser. No. 62/550,379, filed onAug. 25, 2017, entitled “WATER-COOLED LED-BASED LIGHTING METHODS ANDAPPARATUS FOR CONTROLLED ENVIRONMENT AGRICULTURE,” and U.S. ProvisionalApplication Ser. No. 62/635,499, filed on Feb. 26, 2018, entitled“WATER-COOLED LED-BASED LIGHTING METHODS AND APPARATUS FOR CONTROLLEDENVIRONMENT AGRICULTURE.” Each of the aforementioned applications isincorporated herein by reference in its entirety.

BACKGROUND

Controlled Environment Agriculture (CEA) is the process of growingplants in a controlled environment where various environmentalparameters are monitored and adjusted to improve the quality and yieldof the plants grown. Compared to conventional approaches of plantcultivation, CEA may enable year-round production of plants,insensitivity to variable weather conditions, reduce pests and diseases,and reduce the amount of resources consumed on a per plant basis. Acontrolled agricultural environment is typically enclosed, at least inpart, by a building structure such as a greenhouse, a grow room, or acovered portion of a field in order to provide some degree of controlover environmental conditions. One or more artificial lighting systemsare often used in such controlled agricultural environments tosupplement and/or replace natural sunlight that may be obstructed by thebuilding structure or insufficient during certain periods of the year(e.g., winter months). Various types of artificial lighting systems maybe used including, but not limited to, a high intensity discharge lamp,a light emitting diode (LED), and a fluorescent lamp.

SUMMARY

The present disclosure is directed to various implementations of afluid-cooled light emitting diode (LED)-based lighting fixture (alsoreferred to hereafter as a “lighting fixture”) for ControlledEnvironment Agriculture (CEA), respective components of the lightingfixture, and methods relating to the same. The lighting fixture may becoupled to a fluid cooling system (also referred to hereafter as a“coolant circuit”) that flows fluid coolant through the lighting fixtureto capture heat generated by one or more LED modules in the lightingfixture. In this manner, heat generated by the lighting fixture may beremoved from the controlled agricultural environment, thus reducing thecooling load and improving energy efficiency. The lighting fixturedescribed herein may be coupled to one or more other lighting fixturesin a daisy-chain configuration where plumbing, electrical power, andcommunication connections are shared to facilitate the creation of acontinuous electrical circuit and coolant circuit. In someimplementations, the lighting fixture may be coupled to a hydronicssystem that utilizes waste heat generated by the lighting fixture (andextracted from the lighting fixture by the coolant circuit) for variousapplications such as regulating the temperature of the controlledagricultural environment or a space near the controlled agriculturalenvironment. The lighting fixture may also function as an integratedsensor platform by providing electrical power and data communicationconnections to one or more sensors that may monitor various environmentconditions of the controlled agricultural environment.

In one exemplary implementation, a lighting fixture includes a frame(also referred to herein as a “housing”) to mechanically support andhouse various components of the lighting fixture. A light spine isformed onto the frame with features to mechanically couple and securethe lighting fixture to a support structure disposed in the controlledagricultural environment. The frame includes one or more channels andcorresponding coolant pipes that fit into the one or more channels. Thecoolant pipes are formed from copper and used to flow fluid coolantthrough the lighting fixture to remove heat. One or more LED modules aredisposed on the frame to emit photosynthetically active radiation (PAR)for growing plants. A processor is coupled to the frame to facilitatethe operation of the lighting fixture with functions including powerconversion, network connectivity, and data processing. One or moreelectrical power ports are disposed on the frame to supply electricalpower from an external source (e.g., a building electrical supplysystem) to various components of the lighting fixture including the LEDmodules, the processor, and auxiliary devices coupled to the lightingfixture. One or more communication ports are disposed on the frame tofacilitate electrical communication and data transmission.

In some implementations, a coolant pipe may be press-fit or crush-fitinto a channel of a frame to improve thermal contact, thereby increasingthe amount of heat removed by the fluid coolant flowing through thelighting fixture. The coolant pipe of the lighting fixture may becoupled to another coolant pipe of another lighting fixture usingpush-to-connect plumbing fittings. In this manner, multiple lightingfixtures may be coupled to form a continuous coolant circuit. One ormore pumps, regulators, and/or valves may be incorporated into thecoolant circuit to generate and direct the fluid coolant through thecoolant circuit. A heat rejection device, such as a cooling tower, mayalso be incorporated into the coolant circuit to remove heat from fluidcoolant, thus reducing the temperature of the fluid coolant for reuse inthe coolant circuit. The coolant circuit may also be used to remove heatfrom other components in the controlled agricultural environment, suchas a dehumidifier.

In some implementations, a coolant circuit having multiple lightingfixtures may be coupled to a hydronics system to recycle waste heatgenerated by the lighting fixtures and captured by the fluid coolant.The hydronics system may distribute heat to regulate the temperature ofat least a portion of the controlled agricultural environment (e.g., agrowing area) or another space near the controlled agriculturalenvironment (e.g., a residential building, a cogeneration plant, afactory). The hydronics system may include a fluid storage tank to storefluid coolant and one or more piping subsystems to direct relativelycool fluid coolant and relatively hot fluid coolant through the coolantcircuit and/or other spaces. Fluid coolant may also be stored at varioustemperatures for later distribution and/or to regulate the temperatureof the fluid coolant.

In some implementations, a controlled agricultural environment with oneor more fluid-cooled LED-based lighting fixtures does not requireadditional cooling or air-conditioning. In other words, excess heatgenerated in the environment from a variety of heat sources (e.g., thelighting fixtures, the plants themselves, walls of a building structureconstituting the environment, one or more dehumidifiers) is effectivelycaptured by the fluid coolant and removed by a heat rejection device(e.g., a cooling tower) or recycled in a hydronics system. Bysignificantly reducing, or in some instances eliminating, the need forair-conditioning, a significant source of required energy for thecontrolled agricultural environment is accordingly significantly reducedor eliminated. The energy savings may lead to substantial reductions inenergy costs for controlled agricultural environments on a variableenergy budget or increase the energy available to grow larger and cropsand larger crop yields for controlled agricultural environments on afixed energy budget. For example, at least a portion of the energybudget formerly used for cooling/air-conditioning may instead be usedfor additional artificial lighting to provide PAR and thereby promoteplant growth for a greater number of plants.

In various implementations, the lighting fixture disclosed herein mayinclude one or more communication and/or auxiliary power ports, forexample, to provide auxiliary DC power to one or more auxiliary devicescoupled to the port(s). Example of such ports include, but are notlimited to, one or more Power over Ethernet (PoE) ports and/or one ormore Universal Serial Bus (USB) ports to communicatively couple multiplelighting fixtures together and/or support operation of one or moreauxiliary devices (e.g., sensors, actuators, or other externalelectronic devices). Examples of various sensors that may be coupled toone or more lighting fixtures via one or more of the PoE or USB portsinclude, but is not limited to, air temperature sensors, near-infrared(NIR) leaf moisture sensors, hyperspectral cameras, finite spectralcameras, IR leaf temperature sensors, relative humidity sensors, andcarbon dioxide sensors. Other examples of auxiliary devices that may becoupled to one or more lighting fixtures via PoE or USB ports include,but are not limited to, one or more fans, security cameras, smartphones, and multi-spectral cameras (e.g., to analyze soil moisture,nutrient content, leaves of the plants). In this manner, variousauxiliary devices may be particularly distributed in the controlledagricultural environment due to the flexible placement of communicationports on the lighting fixtures.

In some implementations, the processor of the lighting fixture may beused to control one or more auxiliary devices and/or process data fromthe auxiliary devices. The processor may then utilize the data to adjustand control operation of one or more lighting fixtures (e.g., adjustingthe PAR output from the lighting fixture) one or more coolant circuitsor other fluid coolant loops (e.g., adjusting the fluid flow through thecoolant circuit/lighting loop, heating loop, and cooling loops), one ormore fans, one or more dehumidifiers, or one or more air conditioners inthe controlled agricultural environment. In some implementations,various environmental conditions are measured and controlled to providetarget vapor pressure deficits in the environment.

In some implementations, the lighting fixture may be used in a leasedlighting system where a customer pays a recurring fee to rent andoperate one or more lighting fixtures. In one exemplary implementation,the lighting fixture may be communicatively coupled to a license serverthat controls the amount of time the lighting fixtures operatesaccording to payments by the customer. Encryption keys and a tokenexchange with a license server may be used operate the leased lightingsystem for a controlled agricultural environment.

In sum, one example implementation is directed to a A fluid-cooledLED-based lighting fixture, comprising: an extruded aluminum frameincluding at least a first channel, a second channel, and at least oneenclosed cavity formed therein, the extruded aluminum frame furtherincluding a fin protruding from the frame and having a plurality ofholes to facilitate mechanical coupling of the lighting fixture to atleast one support structure; at least one LED light source mechanicallysupported by the extruded aluminum frame; a first copper pipe to carry afluid coolant to extract heat generated by at least the at least one LEDlight source during operation of the lighting fixture, wherein the firstcopper pipe is press-fit into the first channel of the extruded aluminumframe so as to establish a first thermal connection between the firstcopper pipe and the extruded aluminum frame; a second copper pipe tocarry the fluid coolant, wherein the second copper pipe is press-fitinto the second channel of the extruded aluminum frame so as toestablish a second thermal connection between the second copper pipe andthe extruded aluminum frame; control circuitry, disposed in the at leastone enclosed cavity of the extruded aluminum frame, to receive AC powerand to control the at least one LED light source; and a plurality ofports, electrically coupled to at least some of the control circuitry,to provide DC power to at least one auxiliary device coupled to at leastone of the plurality of ports.

Another example implementation is directed to a method for controllingan agricultural environment, the method comprising: A) flowing a fluidcoolant in a coolant circuit, wherein the coolant circuit comprises atleast one LED-based lighting fixture from which the fluid coolantextracts fixture-generated heat as the fluid coolant flows in thecoolant circuit through the at least one LED-based lighting fixture andat least one hydronics loop, coupled to the at least one LED-basedlighting fixture, to facilitate temperature regulation in at least aportion of the agricultural environment; B) irradiating a plurality ofplants with photosynthetically active radiation (PAR) output by at leastone LED-based lighting fixture; and C) sensing at least one condition inthe agricultural environment via at least one sensor communicativelycoupled to the at least one LED-based lighting fixture.

Another example implementation is directed to a method for controllingan agricultural environment, the method comprising: A) flowing a fluidcoolant in a coolant circuit, wherein the coolant circuit comprises atleast one LED-based lighting fixture from which the fluid coolantextracts fixture-generated heat as the fluid coolant flows in thecoolant circuit through the at least one LED-based lighting fixture andat least one hydronics loop, coupled to the at least one LED-basedlighting fixture, to facilitate temperature regulation in at least aportion of the agricultural environment; B) irradiating a plurality ofplants with photosynthetically active radiation (PAR) output by at leastone LED-based lighting fixture; C) sensing at least one condition in theagricultural environment via at least one sensor communicatively coupledto the at least one LED-based lighting fixture, wherein the at least onesensor includes least one of: an air temperature sensor; a near infrared(NIR) sensor; a relative humidity sensor; a camera; a carbon dioxide(CO2) sensor; and an infrared (IR) sensor; and D) controlling at leastone of 1) the PAR output by the at least one LED lighting fixture and 2)a flow of the fluid coolant in at least one of the at least one LEDlighting fixture and the hydronics loop, based at least in part on theat least one sensed condition in C), wherein: the at least one LED-basedlighting fixture includes at least a first copper pipe and a secondcopper pipe forming at least a portion of the coolant circuit; and A)comprises flowing the fluid coolant in opposite directions in the firstcopper pipe and the second copper pipe, respectively.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, allcombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein. It should also be appreciated that terminologyexplicitly employed herein that also may appear in any disclosureincorporated by reference should be accorded a meaning most consistentwith the particular concepts disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

The skilled artisan will understand that the drawings primarily are forillustrative purposes and are not intended to limit the scope of theinventive subject matter described herein. The drawings are notnecessarily to scale; in some instances, various aspects of theinventive subject matter disclosed herein may be shown exaggerated orenlarged in the drawings to facilitate an understanding of differentfeatures. In the drawings, like reference characters generally refer tolike features (e.g., functionally similar and/or structurally similarelements).

FIG. 1 is an illustration of a conventional controlled agriculturalenvironment where one or more HPS lamps are used.

FIG. 2 is an illustration of a conventional controlled agriculturalenvironment where one or more conventional LED-based lighting fixturesare used.

FIG. 3 is an illustration of a controlled agricultural environment whereone or more fluid-cooled LED-based lighting fixtures are retrofit into apre-existing environment, according to some implementations of thedisclosure.

FIG. 4 is an illustration of a controlled agricultural environment whereone or more fluid-cooled LED-based lighting fixtures are coupled to ahydronics system, according to some implementations of the disclosure.

FIG. 5 is a block diagram of a lighting fixture, according to someimplementations of the disclosure.

FIG. 6A is a circuit diagram detailing a first half of an exemplary LEDmodule of a lighting fixture, according to some implementations of thedisclosure.

FIG. 6B is a circuit diagram detailing the second half of the exemplaryLED module of FIG. 6B.

FIG. 7A shows a bottom, front perspective view of a lighting fixture,according to some implementations of the disclosure.

FIG. 7B shows front, bottom, left side, and right side views of thelighting fixture of FIG. 7A.

FIG. 7C shows a cross-sectional view of the lighting fixture of FIG. 7Balong the plane A-A.

FIG. 8A shows a top perspective view of a first lighting fixture coupledto a second lighting fixture and a support structure, according to someimplementations of the disclosure.

FIG. 8B shows a perspective view of a controlled agriculturalenvironment showing multiple rows of fluid-cooled LED-based lightingfixtures coupled together forming a continuous electrical and coolantcircuit, according to some implementations of the disclosure.

FIG. 9A shows an exemplary hydronics system including a fluid storagetank and multiple piping subsystems such as a lighting loop, a heatingloop, and a cooling loop, according to some implementations of thedisclosure.

FIG. 9B shows a portion of an exemplary hydronics system coupled to alighting fixture and a growing area, according to some implementationsof the disclosure.

FIG. 9C shows a controlled agricultural environment where one or morefluid-cooled LED-based lighting fixtures are disposed in avertically-stacked multiple-level growing area and coupled to ahydronics system, according to some implementations of the disclosure.

FIG. 10 shows a side view of a controlled agricultural environment witha plurality of fluid-cooled LED-based lighting fixtures and a pluralityof sensors to facilitate monitoring of environmental conditions,according to some implementation of the disclosure.

FIG. 11A is a block diagram detailing various electronics components ofa processor including a control board, a network board, and a singleboard computer, according to some implementations of the disclosure.

FIG. 11B is a block diagram providing additional detail of the controlboard of FIG. 11A.

FIG. 11C is a block diagram providing additional detail of the networkboard of FIG. 11A.

FIG. 12A is a circuit diagram detailing various electronic components ofa network board, according to some implementations of the disclosure.

FIG. 12B is an expanded view of the Ethernet switch of FIG. 12A.

FIG. 12C is an expanded view of the PoE port of FIG. 12A.

FIG. 12D is a circuit diagram of the PoE controller of FIG. 12A.

FIG. 13 is a circuit diagram of a single board computer, according tosome implementations of the disclosure.

FIG. 14A is a circuit diagram detailing various electrical components ofa control board, according to some implementations of the disclosure.

FIG. 14B is a circuit diagram detailing the bias and control powersupply of the control board of FIG. 14A.

FIG. 14C is a circuit diagram detailing the DC-DC converter of thecontrol board of FIG. 14A.

FIG. 14D is a circuit diagram detailing the AC line sensor of thecontrol board of FIG. 14A.

FIG. 14E is a circuit diagram detailing the DSP of the control board ofFIG. 14A.

FIG. 14F is a circuit diagram detailing the temperature sensor circuitryof the control board of FIG. 14A.

FIG. 14G is a circuit diagram detailing the boost circuit of the controlboard of FIG. 14A.

FIG. 14H is a circuit diagram further detailing the boost circuit ofFIG. 14G.

FIG. 15A is a flow diagram of a contract enforcement method, accordingto some implementations of the disclosure.

FIG. 15B is a flow diagram of a method to update a license in a leasedlighting system, according to some implementations of the disclosure.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various conceptsrelated to, and implementations of, fluid-cooled LED-based lightingmethods and apparatus for controlled environment agriculture. It shouldbe appreciated that various concepts introduced above and discussed ingreater detail below may be implemented in numerous ways. Examples ofspecific implementations and applications are provided primarily forillustrative purposes so as to enable those skilled in the art topractice the implementations and alternatives apparent to those skilledin the art.

The figures and example implementations described below are not meant tolimit the scope of the present implementations to a single embodiment.Other implementations are possible by way of interchange of some or allof the described or illustrated elements. Moreover, where certainelements of the disclosed example implementations may be partially orfully implemented using known components, in some instances only thoseportions of such known components that are necessary for anunderstanding of the present implementations are described, and detaileddescriptions of other portions of such known components are omitted soas not to obscure the present implementations.

Controlled Environment Agriculture (CEA) is the process of growingplants in a controlled environment where various environmentalparameters, such as lighting, temperature, humidity, nutrient levels,and carbon dioxide (CO₂) concentrations are monitored and adjusted toimprove the quality and yield of the plants. Compared to conventionalapproaches of plant cultivation, CEA may enable year-round production ofplants, insensitivity to variable weather conditions, reduce pests anddiseases, and reduce the amount of resources consumed on a per plantbasis. Additionally, CEA may support various types of growing systemsincluding, but not limited to soil-based systems and hydroponicssystems.

A controlled agricultural environment is typically enclosed, at least inpart, by a building structure such as a greenhouse, a grow room, or acovered portion of a field in order to provide some degree of controlover environmental conditions. One or more artificial lighting systemsare often used in such controlled agricultural environments tosupplement and/or replace natural sunlight that may be obstructed by thebuilding structure or insufficient during certain periods of the year(e.g., winter months). The use of an artificial lighting system may alsoprovide yet another measure of control where the intensity and spectralcharacteristics of the lighting system may be tailored to improve thephotosynthetic rates of plants. Various types of artificial lightingsystems may be used including, but not limited to, a high intensitydischarge lamp, a light emitting diode (LED), and a fluorescent lamp.

Artificial lighting systems, however, generate heat, which whendissipated into the environment may contribute significantly to thecooling load of the controlled agricultural environment. In order toaccommodate the higher cooling load and thus maintain the controlledagricultural environment within a desired temperature envelope, thecooling capacity of a cooling system may need to be increased resultingin greater energy consumption. For a controlled agricultural environmenton a variable energy budget, greater energy consumption may lead tohigher energy costs. Alternatively, for a controlled environment on afixed energy budget, a larger portion of the energy budget may beconsumed by the cooling system, thus reducing the energy and capacityavailable to support a larger crop size and yield.

To illustrate the impact excess heat generated by an artificial lightingsystem may have on energy consumption, FIG. 1 shows a conventionalcontrolled agricultural environment with one or more high pressuresodium (HPS) lamps 10, a particular type of high intensity dischargelamp, which irradiates a plurality of plants 900. The exemplarycontrolled agricultural environment shown in FIG. 1 further includes adehumidifier 65 to manage the relative humidity of the environment andan air conditioner 85, which may include a fan coil, compressor, andcondenser. Energy consumption by the air conditioner 85 generallydepends on (1) the total cooling load of the environment and (2) theenergy efficiency ratio (EER) of the air conditioner 85. The EER of anair conditioner is defined as the ratio of the cooling capacity (inWatts) to the input power (in Watts) at a given operating point. The EERwas calculated with a 35° C. (95° F.) outside temperature and an inside(return air) temperature of 26.7° C. (80° F.) and 50% relative humidity.A higher EER indicates the air conditioner 85 is more efficient.

As shown in FIG. 1, the HPS lamps 10 may increase the cooling load ofthe environment by (1) dissipating heat convectively and/or radiativelydirectly into the environment and (2) increasing the relative humidityof the environment and thus, the power input and resultant heatgenerated by the dehumidifier 65. The cooling load in this exemplarycontrolled agricultural environment is about 1315 W. For an EER rangingfrom 3 to 7, the input power for the air conditioner thus ranges from450 to 190 W, respectively. Based on the input power to the HPS lamps 10of 1050 W and the dehumidifier 65 of 265 W, the air conditioner 85 thusconsumes about 13% and 26% of the total energy budget, corresponding toan EER of 7 and 3, respectively.

The amount of heat generated may vary depending on the type of lightingsystem used. However, artificial lighting systems for controlledagricultural environments generally have large power inputs (e.g.,greater than 1000 W) in order to sustain a sufficient level ofphotosynthetically active radiation (PAR). Thus, the heat generated byvarious types of lighting systems may still constitute a large portionof heat produced within the environment. In another example, FIG. 2illustrates a conventional controlled agricultural environment where oneor more conventional LED-based lighting fixtures 12A and 12B irradiate aplurality of plants 900. In this exemplary controlled agriculturalenvironment, the LED-based lighting fixtures 12A and 12B dissipates heatprimarily via convection, which may reduce the power input and heatgenerated by the dehumidifier 65. In this example, the total coolingload is about 1210 W. For an EER ratio ranging from 3 to 7, the inputpower for the air conditioner 85 ranges from 405 W to 175 W. Compared tothe first example, the use of LED-based lighting fixtures 12A and 12Bdecreases the total energy budget of the controlled agriculturalenvironment. However, the proportion of energy used by the airconditioner 85 remains similar to the first example at about 13% and 25%for an EER ratio of 7 and 3, respectively. As shown in the two exemplarycontrolled agricultural environments, artificial lighting systems maygenerate a substantial amount of heat, which may result in airconditioning systems consuming a significant portion of the total energybudget in a controlled agricultural environment.

The present disclosure is thus directed to a fluid-cooled LED-basedlighting fixture. In some implementations, a fluid cooling system may beintegrated into the lighting fixture such that a substantial portion ofthe heat generated by one or more LED's in the lighting fixture iscaptured by the fluid cooling system. In this manner, the amount of heattransferred to the environment by the lighting fixture may besubstantially reduced, thus decreasing the cooling load and the energyinput for any air conditioning systems that may be in the controlledagricultural environment. In some implementations, the fluid coolingsystem may be coupled to a hydronics system to distribute waste heatfrom the lighting fixture to control the temperature of the growing areaor a separate interior space (e.g., a residential building). In someimplementations, two or more lighting fixtures may be connected inseries, or “daisy-chained,” where electrical and piping connections areshared to support a continuous electrical circuit and coolant circuit.The lighting fixture may also provide electrical connections to powerone or more sensors to monitor various environmental conditions. In thismanner, the fluid-cooled LED-based lighting fixture may also function asan integrated sensor platform.

To illustrate the benefits of a fluid-cooled LED-based lighting fixturedisclosed herein, FIG. 3 shows an exemplary implementation of acontrolled agricultural environment 2000A where a lighting fixture 1000is retrofit into a pre-existing environment that includes a dehumidifier65 and an air conditioner 85. While not shown explicitly in FIG. 3, theenvironment may be constituted, at least in part, by a buildingstructure to house a plurality of plants 900, one or more lightingfixtures 1000, and other equipment. The lighting fixture 1000 is cooledby a fluid coolant 800 that circulates through a coolant circuit 570.Heat carried by the fluid coolant 800 is removed by a cooling tower 557located outside of the controlled agricultural environment 2000A. Thecoolant circuit 570 may include one or more pumps, regulators and/orvalves 555 to control the flow of the fluid coolant 800 in the coolantcircuit 570.

As shown in FIG. 3, the one or more pumps, regulators, and/or valves 555may produce a flow of fluid coolant 800 that exhibits a relativelycolder temperature Tc upon entry into the lighting fixture 1000 and arelatively hotter temperature Tx upon exit from the lighting fixture1000. The rise in temperature of the fluid coolant 800 is due, in part,to convective heating of the fluid as it passes through the lightingfixture 1000 due to heat generated from one or more LED modules withinthe lighting fixture 1000. The fluid coolant 800 may thus be used tocapture and transport heat generated by the lighting fixture 1000, whichmay substantially reduce the cooling load of the environment and thepower inputs to the air conditioner 85 and/or the dehumidifier 65. Asshown in FIG. 3, the cooling load for the exemplary controlledagricultural environment 2000A is about 635 W, which is approximately50% the cooling load in the exemplary controlled agriculturalenvironments shown in FIGS. 1 and 2. For an EER ranging from 3 to 7, theinput power for the air conditioner thus ranges from 210 W to 90 W,respectively. Based on the input power to the lighting fixture 1000 of1050 W and the dehumidifier 65 of 160 W, the air conditioner 85 thusconsumes about 7% and 15% of the total energy budget, corresponding toan EER of 7 and 3, respectively.

Although a cooling tower 557 is shown in FIG. 3 to facilitateevaporative cooling of the heated fluid coolant exiting the lightingfixture 1000, it should be appreciated that various types of heatrejection devices may be employed in the coolant circuit 570 to removeheat from the fluid coolant 800. Some examples of heat rejection devicesinclude, but are not limited to, various types of evaporative coolers,“free” coolers, chillers, dry coolers, air source coolers, ground sourceheat exchangers, water source heat exchangers, or any combinations ofthe foregoing.

In another example, FIG. 4 shows an exemplary controlled agriculturalenvironment 2000B where a lighting fixture 1000 is coupled to a coolantcircuit 570 that directs the fluid coolant 800 to a hydronics system501A having multiple plumbing subsystems 700A and 700B (also referred toherein as “hydronics loops”), which regulate and/or maintain thetemperature of various portions of the controlled agriculturalenvironment 2000B and/or space near the controlled agriculturalenvironment 2000B (e.g., a hot pool, the growing area) by utilizing thewaste heat generated by the lighting fixture 1000 as a heat source. Thecoolant circuit 570 may receive heat from the lighting fixture 1000 andother environment sources (e.g., a dehumidifier 65, the ambient air)such that excess heat generated in the environment may be substantiallyremoved, thus further improving the energy savings to operate thecontrolled agricultural environment 2000B. In some implementations, thecooling load may be sufficiently reduced so as to eliminate the need forany air conditioning systems (i.e., there is no air conditioner fancoil, compressor or condenser).

As shown in FIG. 4, the controlled agricultural environment 2000B mayinclude a dehumidifier 65 to regulate the relative humidity of theenvironment. The coolant circuit 570 may direct fluid coolant 800 heatedby the lighting fixture 1000 into the dehumidifier 65 to further removeheat generated by the dehumidifier 65 in a convective manner similar tothe removal of heat from the lighting fixture 1000. The coolant circuit570 may then direct the fluid coolant 800 to the hydronics loops 700Aand 700B, which may be used to heat the plurality of plants 900 and ahot pool, respectively. The coolant circuit 570 may distribute anddirect heated fluid coolant 800 in a controlled manner by one or valves502 before dissipating the remaining heat by the cooling tower 557.

In some implementations, the hydronics system 501A may also be used toregulate the temperature of the ambient environment itself. For example,the hydronics system 501A may be used to heat the controlledagricultural environment 2000B convectively and/or radiatively as thefluid coolant 800 flows through the hydronics system 501. A Furthermore,while FIG. 4 shows a coolant circuit 570 passing through thedehumidifier 65, it should be appreciated that in other implementationsthe coolant circuit 570 need not include the dehumidifier 65, e.g. thecoolant need not flow through the humidifier 65.

An exemplary implementation of a fluid-cooled LED-based lighting fixture1000 is shown in FIG. 5. The lighting fixture 1000 may include a frame1004 to mechanically support and house various components of thelighting fixture 1000. A light spine 1002 may be incorporated onto oneor more sides of the frame 1004 with features to mechanically couple andsecure the lighting fixture 1000 to a support structure disposed withina controlled agricultural environment. One or more coolant pipes 1006may be coupled to the frame 1004, where each coolant pipe 1006 may beused to flow a fluid coolant 800 to cool the lighting fixture 1000. Oneor more LED modules 400 may be disposed on the frame 1004 to emit PARtowards a plurality of plants. A processor 90 may be coupled to theframe 1004 to facilitate the operation of the lighting fixture 1000including, but not limited to power conversion, network connectivity,and data processing. One or more electrical power ports 1010 may bedisposed on the frame 1004 to supply electrical power to variouscomponents of the lighting fixture 1000, including, but not limited tothe LED modules 400, the processor 90, and other sensors that may becoupled to the lighting fixture 1000. One or more communication ports1009 may be disposed on the frame 1004 to facilitate electricalcommunication and data transmission.

The frame 1004 may be a mechanically rigid, hollow structure that formsa substantially enclosed housing. The interior cavity of the frame 1004may be dimensioned to house a plurality of components in the lightingfixture 1000, such as various electronics in the processor 90. The frame1004 may include one or more mounting features within the interiorcavity to securely couple the plurality components to the frame 1004.For example, the frame 1004 may include one or more slots disposedwithin the interior cavity of the frame 1004 and arranged so as tomechanically support at least two opposing edges of a printed circuitboard. Other mounting features may include, but are not limited tomounting posts and mounting stubs.

One or more removable panels may be included in the frame 1004 toprovide access to the interior space. The one or more removable panelsmay be coupled to a portion of the frame 1004 using various types ofcoupling mechanisms including, but not limited to screw fasteners, boltfasteners, clips, and clamps. In some implementations, the frame 1004may form a sufficiently airtight enclosure or cavity to protectcomponents, e.g., electronics, that may be sensitive to theenvironmental conditions of the controlled agricultural environment. Forexample, the controlled agricultural environment may operate at arelative humidity that may cause moisture to condense onto varioussurfaces of the lighting fixture 1000, causing damage to componentsincluding exposed electronics. In instances where the frame 1004 is anairtight enclosure, moisture may be substantially restricted frominfiltrating the interior space of the frame 1004 to reduce thelikelihood of condensation forming onto components disposed within theframe 1004.

The frame 1004 may also include a recessed portion disposed along atleast one side of the frame 1004, e.g., the bottom side, with sidewallsthat at least partially surround one or more LED modules 400. Therecessed portion may be used to direct light emitted by the one or moreLED modules 400 along a preferred direction and angular distribution.For example, the recessed portion may be used to substantiallyilluminate a growing area containing one or more plants located belowthe frame 1004. In some implementations, the surface quality andorientation of the interior surfaces of the sidewalls forming therecessed portion may form an integrated reflector to reflect lightemitted by the one or more LED modules 400. For example, the interiorsurfaces of the sidewalls may be polished to reflect light in asubstantially specular manner and oriented such that light is reflectedtowards a preferred direction, e.g., the growing area.

The frame 1004 may also include one or more channels formed along one ormore sides of the frame 1004 where each channel may be used to secure acorresponding coolant pipe 1006 to the frame 1004. The cross-sectionalshape of the channel may be substantially similar to the cross-sectionalshape of the coolant pipe 1006 to facilitate insertion of the coolantpipe 1006 into the channel. The coolant pipe 1006 may be secured to thechannel of the frame 1004 using several approaches. For example, thecross-section dimensions of the channel may be equal to or smaller thanthe cross-sectional dimensions of the coolant pipe 1006 to facilitate apress fit where the coolant pipe 1006 is secured to the channel viafriction. In other examples, the coolant pipe 1006 may be clamped to theframe 1004 using one or more clamps, which may include, but are notlimited to zip ties and clamps with a worm drive fastener. The clampsmay be removable to allow replacement of the coolant pipes 1006. Thesurface of the one or more channels may also be polished to improvethermal contact with the coolant pipe 1006, thus enabling greater heatdissipation into the fluid coolant 800. In yet other examples, thecoolant pipes 1006 may be adhered or bonded to the frame 1004 usingvarious methods including, but not limited to adhesive bonding, welding,and brazing. Thermal interface material may also be disposed between thechannel and the coolant pipe to improve thermal contact.

The frame 1004 may also be, at least in part, thermally conducting totransfer heat from the one or more LED modules 400 to the coolant pipe1006. In particular, a first portion of the frame 1004 disposed betweenthe LED module 400 and the coolant pipe 1006 may be formed from athermally conducting material with dimensions to (1) reduce the distancebetween the LED module 400 and the coolant pipe 1006 and (2) increasethe lateral cross-sectional area between the LED module 400 and thecoolant pipe 1006. In this manner, the thermal resistance between theLED module 400 and the coolant pipe 1006 may be reduced. In someimplementations, the frame 1004 may be formed entirely from thethermally conducting material to simplify manufacture and assembly. Insome implementations, the first portion of the frame 1004 may be formedfrom a thermally conducting material while the remainder of the frame1004 is formed from another material, such as a polymer in order toreduce material costs.

The frame 1004 may be formed from various metals, ceramics, polymers, orcomposites including, but not limited to, copper, aluminum, stainlesssteel, carbon steel, polyethylene, acrylic, and porcelain. Depending onthe materials used to form the frame 1004, various method of manufacturemay be utilized including, but not limited to extrusion, sandcasting,milling, injection molding, and manual molding. For instances where theframe 1004 is assembled form multiple parts, various coupling mechanismsmay be used for assembly including, but not limited to snap fits, screwfasteners, bolt fasteners, adhesives, brazing, and welding.

The light spine 1002 may be used to secure the lighting fixture 1000 toa support structure in the controlled agricultural environment. Thesupport structure may be various types of structures including, but notlimited to a railing, a suspended platform, a ceiling, and a wall. Thelight spine 1002 may be a protruding fin formed onto the frame 1004 thatincludes one or more holes of varying size to accommodate differentsizes and types of coupling mechanisms used to secure the lightingfixture 1000 to the support structure. The coupling mechanisms mayinclude, but are not limited to bolt fasteners, screw fasteners, hooks,and shackles. The light spine 1002 may be dimensioned to span the lengthof the frame 1004, thus providing multiple locations along the frame1004 to couple the lighting fixture 1000 to the support structure in astable manner. For example, the light spine 1002 may be disposed on thetop side of the frame 1004 with a length that spans the length of theframe 1004. The light spine 1002 may include a plurality of holes wherethe center axis of each hole is parallel to the top side of the frame1004. Multiple bolt fasteners may be installed at each end and thecenter of the light spine 1002 to secure the lighting fixture 1000 to asidewall of a support structure. Multiple light spines 1002 may also bedistributed along the length of the frame 1004 or on multiple sides ofthe frame 1004 to allow the lighting fixture 1000 to be coupled todifferent support structures.

As described above, the coolant pipe 1006 may be used to flow fluidcoolant 800 to capture heat generated by the LED module 400. The coolantpipe 1006 may be dimensioned to have a length longer than the frame 1004such that a portion of the coolant pipe 1006 may extend beyond the sidesof the frame 1004 to facilitate coupling of the coolant pipe 1006 to apipe from a coolant circuit, a hydronics system, or another lightingfixture 1000. Various types of coupling mechanisms may be used to couplethe coolant pipe 1006 to another pipe including, but not limited tothreaded fittings, where the ends of the coolant pipe 1006 havecorresponding threads, and bolt fasteners, where the end of the coolantpipe 1006 have a flange that mates to a corresponding flange on anotherpipe. In a preferred implementation, push-to-connect plumbing fittingsmay be used as a coupling mechanism where the ends of the coolant pipe1006 are left bare. In this manner, internal seals and O-rings do notneed to be used.

Multiple coolant pipes 1006 may be incorporated into the frame 1004where each coolant pipe 1006 may be used to flow fluid coolant 800 alongthe same or opposing directions. For example, the lighting fixture 1000may include two coolant pipes 1006 disposed on opposing sides of theframe 1004. For a lighting fixture 1000 that supports multiple LEDmodules 400, an opposing flow configuration (e.g., fluid coolant 800flows in opposing directions between the two coolant pipes 1006) maymore uniformly remove heat from the multiple LED modules 400. Incomparison, a same flow configuration will result in more heat removedfrom the LED module 400 closest to the fluid coolant 800 input and lessheat removed from the LED module 400 furthest from the fluid coolant 800input. Additionally, the opposing flow configuration may more readilyfacilitate implementation of a closed coolant circuit. For example, thetwo coolant pipes 1006 may be connected at one end by a plumbing fittingsuch that fluid coolant 800 entering the lighting fixture 1000 flowsthrough a first coolant pipe 1006 and then a second coolant pipe 1006serially before exiting the lighting fixture 1000 on the same side.

The coolant pipe 1006 may be formed from various materials includingcopper, aluminum, and stainless steel. In a preferred implementation,the coolant pipes 1006 may be formed from copper to reduce algae growth,fouling, and corrosion. Thus, by coupling copper coolant pipes 1006using the push-to-connect plumbing fittings described above, the fluidcoolant 800 may pass through a coolant circuit made up of only copperwithout contacting other materials in the lighting fixture (e.g., analuminum frame 1004).

The cross-sectional dimensions of the coolant pipe 1006 may varydepending on multiple factors including, but not limited to a desiredflow rate, fluid coolant properties (e.g., dynamic viscosity, density),and a desired type of flow. For example, it may be desirable for thefluid coolant to be in a turbulent flow regime, which engenders a higherheat transfer coefficient, thus dissipating more heat from the lightingfixture 1000. In some implementations, the cross-sectional dimensions ofthe coolant pipe 1006 may be chosen such that a particular Reynold'snumber, Re, is greater than a desired threshold (e.g., Re>4000 forturbulent flow) for a given pump power and coolant circuit geometry. Theinterior surface of the coolant pipe 1006 may also be roughened toincrease the surface area and the convective heat transfer coefficient.The effective depth and pitch of the interior surface roughness may bechosen so as to not substantially increase pumping requirements (e.g.,due to a larger pressure drop) and maintains wettability of the interiorsurface to the fluid coolant 800 (e.g., remains hydrophilic,oleophilic).

The fluid coolant 800 used to capture and carry heat from the lightingfixture 1000 may be chosen based on several factors. First, it ispreferable for the fluid coolant 800 to exhibit a high thermalconductivity and a high specific heat in order to increase heatdissipation from the LED module 400 to the fluid coolant 800. Second,the fluid coolant 800 should remain in a liquid phase within theoperating temperature and pressure range of the controlled agriculturalenvironment. For example, the fluid coolant 800 should not freeze orboil as it passes through the lighting fixture 1000, the coolantcircuit, the hydronics system, or a cooling tower. Third, the fluidcoolant 800 should also be chosen so as not to substantially corrode thecoolant pipe 1006. For controlled agricultural environments, the fluidcoolant 800 may be various fluids including, but not limited to water,mineral oil, glycol, and mixtures.

The lighting fixture 1000 also may include one or more communicationand/or auxiliary power ports, for example, to provide auxiliary DC powerto one or more auxiliary devices coupled to the port(s), and/orfacilitate communications between the lighting fixture and the one ormore auxiliary devices. Example of such ports include, but are notlimited to, one or more Power over Ethernet (PoE) ports and/or one ormore Universal Serial Bus (USB) ports.

For example, the lighting fixture 1000 may include at least oneelectrical power port 1010 to supply electrical power to variouscomponents in the lighting fixture 1000 (e.g., the LED module 400)and/or various components electrically coupled to the lighting fixture1000 (e.g., other lighting fixtures 1000 or auxiliary sensors). Theelectrical power port 1010 may receive as input alternating current (AC)power, such as from a building electrical supply system, which may beconverted into direct current (DC) power via the processor 90. Theprocessor 90 may include electronics to facilitate conversion between DCand AC power, as will be discussed in greater detail below.

One or more communication ports 1009 may also be used in the lightingfixture 1000 to facilitate data transmission to and from the lightingfixture 1000. For example, the communication port 1009 may be used toremotely control various aspects of the lighting fixture 1000 including,but not limited to adjustments to electrical power (e.g., high voltageand low voltage modes), adjustments to the spectral content of the lightemission (e.g., directing more power to blue or red LED elements), andcommands to operate auxiliary sensor devices (e.g., frequency of datarecording). In another example, the communication port 1009 may be usedto send various status and monitoring data to a remote user including,but not limited to electrical power consumption, temperature, and datameasured by auxiliary sensor devices. The data received and transmittedby the communication port 1009 may be managed, in part, by the processor90, as will be discussed in more detail below.

The communication port 1009 may accommodate various types of electricalcabling including, but not limited to universal serial bus (USB) cablesand Power over Ethernet (PoE) cables. In some implementations, multiplecommunication ports 1009 including both USB and PoE ports may be used toenable greater flexibility and compatibility with more types of cablingand auxiliary devices. One or more communication ports 1009 may bedisposed on one or more sides of the frame 1004. For example, a set ofcommunication ports 1009 may be disposed on opposite sides of the frame1004 (e.g., left and right sides or front and rear sides) to facilitateconnectivity between a plurality of lighting fixtures 1000 in adaisy-chain configuration. Communication ports 1009 may also be disposedon the frame 1004 where auxiliary sensors are likely to be deployed. Forexample, communication ports 1009 may be disposed on the bottom side ofthe frame 1004 to provide electrical connection to auxiliary sensorsthat are used to monitor ambient conditions near the plants locatedbelow the lighting fixture 1000. In some implementations, thecommunication port 1009 may also supply DC power. For example, thelighting fixture 1000 may include a USB port that may electrically poweran auxiliary sensor device and receive data measured by the auxiliarysensor device through the same communication port 1009.

The LED module 400 may include one or more LED elements arranged into anarray. The one or more LED elements of the LED module 400 may each emitlight at a particular wavelength such that in combination, the LEDmodule 400 irradiates plants with light at multiple wavelengths tailoredto improve various aspects related to the growth of plants and operationof the controlled agricultural environment including, but not limited toimproving photosynthetic rates of the plants, growth modification, andultraviolet (UV) sterilization. The one or more LED elements may beassembled onto the frontside of a printed circuit board. An exemplarycircuit layout of an LED module 400 according to one inventiveimplementation is shown in FIGS. 6A and 6B, which illustrates therespective halves 400A1 and 400A2 of the LED module 400A. As shown, theLED module 400A may include multiple LED elements that are distributedacross the printed circuit board.

The printed circuit board may be a metal core printed circuit board(MCPCB) to facilitate heat dissipation generated by the one or more LEDelements. The LED module 400 may be coupled to the frame 1004 such thatthe backside of the printed circuit board is in contact with the bottomside of the frame 1004 located in the recessed portion as describedabove. The LED module 400 may be coupled to the frame 1004 using variouscoupling mechanisms including, but not limited to screw fasteners, boltfasteners, clips, and clamps. The coupling mechanism may be adjustedsuch that a clamping force is applied to the LED module 400, thusimproving the thermal contact between the LED module 400 and the frame1004. Additionally, thermal interface material may also be placedbetween the LED module 400 and the frame 1004 (e.g., at MCPCB interface1011) to improve thermal contact.

In some implementations, the lighting fixture 1000 may also include anoptic located on the recessed portion of the frame 1004, which coversthe LED module 400. The optic may be used to modify the direction andangular distribution of the light emitted by the LED module 400. Forexample, a portion of the optic may have a convex surface to focus lightemitted from the LED module 400 onto plants located directly below thelighting fixture 1000. The optic may be coupled to the frame 1004 usingvarious coupling mechanisms including, but not limited to screwfasteners, bolt fasteners, clips, and clamps. In some implementations,the optic may form a substantially airtight enclosure around the LEDmodule 400, thus substantially isolating the LED module 400 from theambient environment in the controlled agricultural environment. Similarto the airtight enclosure that may be formed by the frame 1004, theoptic may reduce moisture infiltration, thus reducing the risk ofcondensation damaging the LED module 400.

An exemplary lighting fixture 1000 according to one inventiveimplementation is shown in FIGS. 7A-7C. FIG. 7A shows a bottomperspective view of the lighting fixture 1000 and FIG. 7B shows a front,bottom, left and right side view of the lighting fixture 1000. As shown,the lighting fixture 1000 includes a frame 1004 dimensioned to supportthree LED modules 400A, 400B, and 400C positioned in a row and disposedon the bottom side of the frame 1004. A light spine 1002 may be formedon the top of the frame 1004 that substantially spans the entire lengthof the frame 1004. The light spine 1002 may include a plurality ofdifferent sized holes to facilitate coupling of the lighting fixture1000 to a support structure in the controlled agricultural environment.The left and right-side panels of the frame 1004 may be secured by aplurality of screw fasteners and hence, may be removed to allow accessinto the interior cavity of the frame 1004. The left side panel of theframe 1004 may include two communication ports 1009, e.g., a USB port1012A and a PoE port 1008C. The right-side panel of the frame 1004 mayalso include two communication ports 1009, e.g., two PoE ports 1008A and1008B, as well as an electrical power port 1010. Two communicationports, e.g., a USB port 1012B and a PoE port 1008D, may be disposed onthe bottom side of the frame 1004 to facilitate connectivity toauxiliary senor devices that may be used to monitor ambient conditionsnear the plants. The lighting fixture 1000 also includes two coolantpipes 1006A and 1006B disposed along the front and rear sides of theframe 1004. The frame 1004 may be formed from an aluminum extrusion toinclude a corresponding pair of channels. The coolant pipes 1006A and1006B, which may be formed form copper, may be press-fit or crush-fitinto the corresponding channels. In this manner, the likelihood thatfluid coolant flowing through the coolant pipes 1006A and 1006B contactsthe frame 1004 is substantially reduced.

FIG. 7C shows a cross-sectional view of the lighting fixture 1000 wherethe coolant pipes 1006A and 1006B are shown to be press-fit into thechannels of the frame 1004. Thermal interface material 1007 may bedisposed between the channels and the coolant pipes 1006A and 1006B toimprove thermal contact. The LED modules 400A-400C are disposedsubstantially in a recessed portion of the bottom side of the frame 1004and in close proximity to the coolant pipes 1006A and 1006B tofacilitate heat dissipation. As shown, a small portion of the frame1004, which is formed from a thermally conducting material, is presentbetween the coolant pipes 1006A and 1006B and the LED modules 400A-400C.FIG. 7C also shows mounting features 1014 used to support variouscontrol circuitry boards 100, 200, and 300, which are collectivelyreferred to hereafter as a processor 90. The mounting features 1014 area pair of protruding slots disposed along the front and rear sides ofthe frame 1004, which are dimensioned to support the opposing edges ofthe processor 90. The processor 90 is positioned above the coolant pipes1006A and 1006B and LED modules 400A-400C in order to reduce thermaleffects due to heat generated by the LED modules 400A-400C. An optic1020 is also included, which may be coupled to the frame 1004 via aplurality of screw fasteners. The optic 1020 may be a transparent lenswith a convex surface used to redirect light emitted by the LED modules400A-400C along a desired direction and angular distribution. The optic1020 may also substantially enclose and isolate the LED modules400A-400C from the surrounding ambient environment.

As described above, the lighting fixture 1000 may be coupled to otherlighting fixtures 1000 in a daisy-chain configuration where electricaland piping connections are shared to facilitate assembly of a continuouselectrical circuit and coolant circuit. For the coolant circuit, thedaisy-chain configuration may be in series where the fluid coolant 800exiting from one lighting fixture 1000 flows into a subsequent lightingfixture 1000 within the daisy-chain. The temperature of the fluidcoolant 800 may increase further due to heat generated from the LEDmodules 400 of the subsequent lighting fixture 1000. It should beappreciated that so long as the temperature of the coolant fluid 800 isless than the temperature of the LED modules 400 in the lighting fixture1000, the fluid coolant 800 may still capture heat from the lightingfixture 1000. Furthermore, in some implementations, heat rejectiondevices may be interspersed along the coolant circuit to reduce thetemperature of the fluid coolant 800 and maintain sufficient heatdissipation as the fluid coolant 800 passes through multiple lightingfixtures 1000. An exemplary implementation detailing the manner in whichtwo lighting fixtures 1000 and 1000-B may be coupled in a daisy-chainconfiguration is shown in FIG. 8A. In some implementations, the lightingfixture 1000 may be coupled to a support structure 999 using a boltfastener 1027 placed through a hole in the light spine 1002 and securedto the side of the support structure 999 as shown in FIG. 8A.

The coolant pipes 1006A and 1006B of the lighting fixture 1000 may becoupled to a corresponding set of coolant pipes 1006A-B and 1006B-B fromthe other lighting fixture 1000-B using one or more intermediate pipes.As shown in FIG. 8A, the pair of coolant pipes 1006B and 1006B-B (1006Aand 1006A-B) may be connected via a single intermediate pipe 1040B(1040A). Each intermediate pipe 1040B (1040A) may have push-to-connectfittings 1025A (1025B) disposed on both ends to facilitate connection tothe coolant pipes 1006B and 1006B-B (1006A and 1006A-B). The shape ofthe intermediate pipe may vary depending on the desired distance andorientation between lighting fixtures 1000 and 1000-B. For example, thelength of the intermediate pipe may be longer in order to space thelighting fixtures 1000 and 1000-B further apart to provide greater arealcoverage or to traverse a gap separating two separate growing areas. Inanother example, the intermediate pipe may be curved such that thelighting fixtures 1000 and 1000-B are oriented at an angle relative toone another, e.g., 90 degrees, to accommodate variable shaped growingareas. In yet another example, the intermediate pipe may besubstantially U-shaped to couple two parallel rows of lighting fixtures1000 where the lighting fixtures 1000 and 1000-B are the last lightingfixtures 1000 in each respective row. In this manner, the coolantcircuit may be continuous for multiple rows of lighting fixtures 1000.

Electrical power may be supplied to multiple lighting fixtures 1000through a single power cable. An exemplary power cable 1030 coupled tothe lighting fixture 1000 is shown in FIG. 8A. In some implementations,the power cable 1030 may be rated to support a particular electricalpower and current input. For example, the power cable 1030 may be ratedto supply at least 1000 W of electrical power and up to 15 A of current.Depending on the power and current requirements of the lighting fixture1000, the power cable 1030 may be used to power multiple lightingfixtures 1000, thus reducing the amount of cabling and the number ofelectrical terminals (e.g., electrical outlets) that need to beinstalled in the controlled agricultural environment.

The lighting fixture 1000 may also be communicatively coupled to anotherlighting fixture 1000 to facilitate transmission of data and controlsignals to multiple lighting fixtures 1000. As shown in FIG. 8A, anEthernet cable 1060 may be used to couple the PoE port 1008A of lightingfixture 1000 to the PoE port 1008C-B of lighting fixture 1000-B. Each ofthe lighting fixtures 1000 and 1000-B may include a processor to managethe flow of data and/or control signals. In some implementations, thelighting fixture 1000 may be used as a piggyback to facilitate thetransfer of data and/or control signals to another lighting fixture 1000located further along the daisy-chain. In this manner, multiple lightingfixtures 1000 spanning a large area may be communicatively coupled to afewer number of network nodes (e.g., hubs, switches, routers) andwithout using excessive amounts of network cabling.

An exemplary arrangement of lighting fixtures 1000 in a controlledagricultural environment 2000 is shown in FIG. 8B. Multiple lightingfixtures 1000 may be arranged along a row spanning a growing areadefined by the dimensions of a shelf 902A. Each lighting fixture 1000 inthe row may be coupled to a support structure 999A disposed above theshelf 902A. The lighting fixtures 1000 in the row may be coupledtogether in a daisy chain configuration, as described above.Intermediate piping may be used to couple adjacent lighting fixtures1000 such that fluid coolant 800 may circulate through the multiplelighting fixtures 1000 in a continuous manner from a single inlet andoutlet for the row. One or more power cables may be used to supplyelectrical power to the lighting fixtures 1000. Ethernet cabling may beused to communicatively couple the lighting fixtures 1000 in a serialmanner and to a common network node. As shown in FIG. 8B, the controlledagricultural environment 2000 may include multiple rows of lightingfixtures 1000 supported by support structures 999A-999E arranged abovecorresponding rows of shelves 902A-902E. The controlled agriculturalenvironment 2000 may further include a fan 75, dehumidifiers 65A and65B, and air conditioning ducts 85A and 85B for one or more airconditioners.

As previously shown in the exemplary controlled agriculturalenvironments 2000A and 2000B in FIGS. 3 and 4, respectively, thelighting fixture 1000 may be incorporated into a coolant circuit 570 tofacilitate the flow of fluid coolant 800 such that heat may becontinuously removed from the lighting fixture 1000. In someimplementations, the coolant circuit 570 may be designed tosubstantially remove heat from only the lighting fixture 1000 and is notintended to thermally interact with other components or regions of thecontrolled agricultural environment 2000A, as shown in the coolantcircuit 570 in FIG. 3 for a retrofit application. In someimplementations, however, the coolant circuit 570 may include additionalpiping subsystems designed to redistribute heat to a space near orwithin the controlled agricultural environment, such as the hydronicsloops 700A shown in FIG. 4 for a hydronics application, and/or to storeheat captured by the lighting fixture 1000 for later use.

A piping subsystem may be branched from the coolant circuit 570 suchthat the flow of fluid coolant 800 may be controllably adjusted (e.g.,by a valve and a separate pump) without affecting the flow of fluidcoolant 800 through the coolant circuit 570 and hence, without affectingthe removal of heat from the lighting fixture 1000. However, in someinstances, a piping subsystem may be placed in series with the coolantcircuit 570 where the piping subsystem is also used on a continualbasis. Some exemplary instances of a piping subsystem being used inseries with the coolant circuit 570 includes, but is not limited to aheating system for a hot water system in a residential space, storingheat from the fluid coolant 800 in a thermal energy storage system, andcharging a battery by converting heat from the fluid coolant 800 intoelectricity (e.g., using a thermoelectric device).

FIG. 9A shows an exemplary hydronics system 501 that may be used inconnection with a coolant circuit 570 as well as in otherimplementations of a controlled agricultural environment where one ormore lighting fixtures 1000 are used. As shown, the hydronics system 501may include a fluid storage tank 500 to store fluid coolant 800, whichmay be disposed internally or externally to the controlled agriculturalenvironment. In some implementations, the fluid storage tank 500 mayinclude separate compartments for relatively cooler fluid coolant 800and relatively hotter fluid coolant 800 with sufficient thermalinsulation to substantially thermally isolate the compartments from oneanother and the surrounding environment. The fluid storage tank 500 mayalso be dimensioned to have a sufficiently large storage capacity suchthat the thermal time constant of the fluid storage tank 500 meets adesired rate of change in temperature during operation. For example, itmay be desirable for the temperature of the fluid coolant 800 stored inthe fluid storage tank 500 to remain substantially unchanged (e.g., 1°C. per hour) throughout the day to reduce fluctuations in the amount ofheat supplied to various piping subsystems. However, if adjustments tothe fluid coolant 800 temperature are desired, the amount of time neededfor the adjustments to occur may be prohibitive due to the long thermaltime constant. In such instances, multiple fluid storage tanks 500, eachhaving a smaller capacity and thus a shorter thermal time constant, maybe used instead.

Three submersible pumps 560A, 560B, and 560C may be disposed within thefluid storage tank 500 to pump fluid coolant 800 through threecorresponding piping subsystems, namely, the coolant circuit 570 (alsoreferred to in FIG. 9A as a “lighting loop”), a heating loop 512, and acooling loop 514. The lighting loop 570 associated with the pump 560A isresponsible for providing relatively cooler fluid coolant from the fluidstorage tank 500 to one or more lighting fixtures 1000 (e.g., via thecoolant circuit 570 as shown in FIGS. 3 and 4) and returning relativelyhotter fluid coolant 800 from the one or more lighting fixtures 1000 tothe fluid storage tank 500. In this manner, the lighting loop 570 mayfunction as a heat source to heat fluid coolant 800 stored in the fluidstorage tank 500 with heat being subsequently distributed to otherpiping subsystems. In some implementations, the lighting loop 570 may beused to heat at least a portion of the controlled agriculturalenvironment 2000C via natural convection or thermal radiation toregulate and maintain temperature of the portion within a desiredtemperature envelope.

In some implementations, a secondary heating loop may be incorporatedinto the lighting loop 570 to more directly and controllably heat aportion of the controlled agricultural environment 2000C that may not beproximate to the lighting loop 570 (e.g., a growing area, as shown inFIG. 4). For example, the secondary heating loop may include a pump, afan, and a fan coil. The pump may generate a flow of relatively hotterfluid coolant 800 through the fan coil, thus heating the fan coil. Thefan may then generate a flow of hot air, thus heating the portion of thecontrolled agricultural environment 2000C via forced convection. Inanother example, the secondary heating loop may be routed through theroot zone of the growing area to heat the soil or nutrient solution to adesired temperature via a combination of convection and conduction (e.g.see the hydronics loop 700A in FIG. 4). The secondary heating loop mayinclude a flow controlling device (e.g., a valve) to control the amountof heat added to the portion of the controlled agricultural environment.For example, the secondary heating loop may be coupled to a thermostatthat adjusts the heat added according to a day/night cycle.

The heating loop 512 associated with the pump 560B may also be used toheat a portion of the controlled agricultural environment 2000C oranother space located separately to the controlled agriculturalenvironment 2000C. For example, the heating loop 512 may be coupled to aheating, ventilation, and air conditioning (HVAC) system in a buildingto regulate the interior climate of the building, a heating system in amanufacturing plant to offset gas or electricity consumption, or acogeneration plant to produce electricity and high-grade heat. In someimplementations, the heating loop 512 may also be coupled to a heatstore 530, which may provide additional capacity to store heat forfuture use by the controlled agricultural environment 2000C or anotherspace.

The cooling loop 514 associated with the pump 560C may be used to coolthe fluid coolant 800 stored in the fluid storage tank 500. In thismanner, the temperature of the relatively cooler fluid coolant 800entering the lighting loop 570 may be regulated and maintained, whichmay reduce the effects of thermal drift over time where the temperatureof the relatively cooler fluid coolant 800 increases, thus reducing theamount of heat removed from the one or more lighting fixtures 1000. Insome implementations, the cooling loop 514 may be a piping subsystemthat captures heat to an exterior environment via natural convection andradiation along the length of the cooling loop 514. In someimplementations, a heat rejection device may be incorporated into thecooling loop 514 to facilitate cooling of the fluid coolant 800. Varioustypes of heat rejection devices may be used including, but not limitedto cooling towers (e.g., see the cooling tower 557 in FIG. 3 or FIG. 4),evaporative coolers, “free” coolers, chillers, dry coolers, air sourcecoolers, ground source heat exchangers, water source heat exchangers, orany combinations of the foregoing. In some implementations, the coolingloop 514 may also be coupled to a cold store 520, which may provideadditional capacity to store relatively cooler fluid coolant 800 forfuture use by the controlled agricultural environment 2000C or anotherspace.

In various implementations described herein, the temperature of thefluid coolant 800 stored in the fluid storage tank 500 and flowingthrough the lighting loop 570, heating loop 512, cooling loop 514, andone or more secondary loops coupled to any of the lighting loop 570,heating loop 512, cooling loop 514 may vary within an appreciabletemperature range. In some implementations, the temperature of the fluidcoolant 800 may range from about 20° C. to about 50° C. The flow rate ofthe fluid coolant 800 may range from about 1 gallon per minute to about3 gallons per minute through the lighting loop 570. Similar orsignificantly different (e.g., higher) flow rates may be used by theheating loop 512 and the cooling loop 514. Furthermore, the variouspiping subsystems (e.g., the lighting loop 570, the heating loop 512,and the coolant loop 514) may be controlled via at least one of a pump,regulator, and/or valves. The at least one of a pump, regulator, and/orvalves may be operated on various time cycles (e.g., daily, weekly,monthly, seasonal, other periodicities, or any combination thereof) toregulate and maintain desired thermal conditions, which may be dynamicas a function of time, in the controlled agricultural environment 2000C.

Additionally, while three piping subsystems are shown in FIG. 9A, itshould be appreciated that any number and combination of pipingsubsystems may be used with the coolant circuit 570. For example, one orboth of the heating loop 512 and the cooling loop 514 may be used inconjunction with the lighting loop 570. It should also be appreciatedthat while three submersible pumps 560A-560C are shown in FIG. 9A, anynumber of pumps may be used for a particular piping subsystem and thepumps 560A-560C may also be disposed externally to the fluid storagetank 500. The pumps may be various types of pumps including, but notlimited to piston pumps, end-suction pumps, diaphragm pumps, gear pumps,lobed pumps, flexible-vane pumps, nutating pumps, peristaltic pumps,centrifugal pumps, diffuser pumps, propeller pumps, and peripheralpumps.

An exemplary implementation of a hydronics system 501B coupled to alighting fixture 1000 and a coolant circuit (“lighting loop”) 570 in acontrolled agricultural environment 2000D is shown in FIG. 9B. Thehydronics system 501B may include a fluid storage tank 500 havingcontained therein a submersible pump 560. The submersible pump 560 isused to pump relatively cooler fluid coolant 800 into a lighting loop570, where the fluid coolant 800 is then heated as it passes through thelighting fixture 1000. Subsequently, the relatively hotter fluid coolant800 exits the lighting loop 570 and enters the fluid storage tank 500for storage. It should be appreciated that so long as the temperature ofthe fluid coolant 800 stored in the fluid storage tank 500 is less thanthe temperature of the fluid coolant 800 entering the fluid storage tank500 from the lighting loop 570, heat generated by the lighting fixture1000 may be removed. Over time, if the temperature of the fluid coolant800 increases, the amount of heat that may be removed may decrease dueto a smaller temperature difference. Thus, a heat rejection device mayneed to be incorporated into the hydronics system 501B to regulate thetemperature of the fluid coolant 800 stored in the fluid storage tank500.

The hydronics system 501B shown in FIG. 9B may also include a secondaryheating loop 700C coupled to the portion of the lighting loop 570 whererelatively hotter fluid coolant 800 heated by the lighting fixture 1000flows through (e.g., similar to the hydronics loops 700A and 700B shownin FIG. 4). As shown, the secondary heating loop 700C may include a pump704 and an electric fan with a fan coil 702. The pump 704 generates aflow of the relatively hotter fluid coolant 800 through the fan coil,thus heating the fan coil. The electric fan 702 may then blow heated airtowards a plurality of plants 900 located below the lighting fixture1000 to increase the temperature of the growing area as desired. Thesecond heating loop 700C may be controlled using one or morecontrollable valves to toggle the secondary heating loop 700C and toadjust the temperature of the air blown by the electric fan 702.

Another exemplary implementation of a hydronics system 501C disposed ina controlled agricultural environment 2000E is shown in FIG. 9C. Asshown, the controlled agricultural environment 2000E may have avertically-stacked multiple-level growing area. Each level of thegrowing area may include one or more lighting fixtures 1000 coupled to alighting loop 570. The lighting loop 570 may be coupled to a fluidstorage tank 500, which may again contain therein a submersible pump.Similar to the controlled agricultural environment 2000D of FIG. 9B, thehydronics system 501C may include secondary heating loops to separatelyheat each growing area in each level. The portions of the lighting loop570 corresponding to each level may be coupled using a plumbing fittingwith multiple inlets and outlets. Additionally, the portion of thelighting loop 570 coupled to the fluid storage tank 500 may support ahigher flow rate to account for a reduction in flow rate once the fluidcoolant 800 flows into each respective level of the growing area.

In some implementations, the lighting fixture 1000 may also function asa sensor platform supporting one or more sensors used to monitorenvironmental conditions in the controlled agricultural environment. Theprocessor 90 in the lighting fixture 1000 may supply and regulateelectrical power to the sensor through the communication ports 1009(e.g., a USB port and a PoE port). The processor 90 may also includeelectronics to convert AC power to DC power, as will be described below,thus obviating the need for a separate AC to DC converter in each sensordeployed in the controlled agricultural environment. The processor 90may also be used to manage data communications, including sendingcontrol signals to the sensor and receiving sensory data measured by thesensor for processing and/or transmission to a remote device (e.g., aremote computer or server). In this manner, the lighting fixture 1000may provide integration of one or more sensors of various types,supplementing the need for separate power and data communicationssystems. Furthermore, the data measured by the one or more sensors maybe used to adjust and control operation of one or more lighting fixtures1000 (e.g., adjusting the PAR output from the lighting fixture 1000),one or more coolant circuits or other fluid coolant loops (e.g.,adjusting the fluid flow through the coolant circuit/lighting loop,heating loop, and cooling loops shown in FIG. 9A), one or more fans, oneor more dehumidifiers, or one or more air conditioners in the controlledagricultural environment. In some implementations, various environmentalconditions are measured and controlled to provide target vapor pressuredeficits in the environment.

An exemplary implementation of a controlled agricultural environment2000 detailing the integration of various sensors via multiple lightingfixtures 1000 is shown in FIG. 10. Similar to FIG. 8B, multiple lightingfixtures 1000 may be mounted to a support structure 999 disposed above aplurality of plants 900 arranged on a shelf 902. The controlledagricultural environment 2000 may include one or more dehumidifiers 65,one or more air conditioners 85, and one or more fans 75. A variety ofsensors may be supported by the lighting fixture 1000 including, but notlimited to an air temperature sensor 80A, a near infrared (NIR) leafmoisture sensor 80B, a relative humidity sensor 80C, a hyperspectralcamera 80D, a carbon dioxide sensor 80E, an infrared (IR) leaftemperature sensor 80F, an airflow sensor 80G, and a root zonetemperature sensor 80H. The hyperspectral camera 80D refers to a type ofcamera that measures light within numerous energy bands (e.g., hundreds)where each band is narrower (e.g., 10 nm) than conventional imagingsystems. Finite spectral cameras (also referred to as multispectralcameras) may also be used in the controlled agricultural environment2000 to measure light using a fewer number of energy bands (e.g. 3 to10) where each band is broader (e.g., greater than 20 nm). The camerasutilized in the controlled agricultural environment 2000 may measurelight across various portions of the electromagnetic spectrum including,but not limited to ultraviolet, visible, near-infrared, mid-infrared,and far-infrared wavelengths. The lighting fixture 1000 may also be usedto support other auxiliary devices including, but not limited to one ormore fans, security cameras, smart phones, and multi-spectral cameras(e.g., to analyze soil moisture and nutrient content). In this manner,various auxiliary devices may be distributed in the controlledagricultural environment due to the flexible placement of communicationports 1009 on the respective lighting fixtures 1000.

The processor 90 may be used to facilitate multiple functionalitiespertinent to the operation of the lighting fixture 1000 including, butnot limited to power conversion, network connectivity, and dataprocessing in the operation of the lighting fixture 1000. In someimplementations, the processor 90 may be comprised of discreteelectronics assemblies that are electrically coupled together where eachelectronics assembly provides one or more distinct functionalities. Forexample, FIG. 11A shows a block diagram detailing various electroniccomponents and circuitry in the processor 90 to meet thesefunctionalities according to one inventive implementation. The processor90 may include a control board 100, a network board 200, and a singleboard computer 300.

The control board 100 may be used to regulate and distribute electricalpower to other components of the lighting fixture 1000. As shown in FIG.11A, the control board 100 may receive AC power through an electricalpower port 1010 and convert the AC power to DC power. The control board100 may then supply DC power and other control signals to otherelectronics in the lighting fixture 400. For example, the control board100 may be directly coupled to multiple LED modules 400A, 400B, and 400Cvia ports/connectors 104A, 104B, and 104C, respectively, on the controlboard 100. The control board 100 may also be coupled to the networkboard 200, providing both electrical power and control signals to thenetwork board 200. The control board 100 may also include onboardmemory, in which digital signal processing (DSP) firmware 152 is storedto facilitate generation of control signals as described below.

A more detailed block diagram of the control board 100 in FIG. 11A isshown in FIG. 11B. The control board 100 may include afuse/electromagnetic interference (EMI) filter 153 to provide safety andreduce noise input into the lighting fixture 1000. A rectifier 157 maybe used to convert AC power to DC power. An AC line sensor 155 may beused to monitor the voltage and current of the DC power input. DC powermay then be passed directly to a bias and control power supply 156,which may be used to distribute DC power to other components of thelighting fixture 1000 including the network board 200 and a digitalsignal processor (DSP) 150. A DC-DC converter 158 may also be includedto supply different voltage inputs to the network board 200. Forexample, the bias and control power supply 156 may supply 48 V and 5 Vto power different circuitry on the network board 200 and the singleboard computer 300. The 5 V input may be down converted from the 48 Vline via the DC-DC converter 158. The DSP 150 may provide controlsignals by executing the firmware 152 described above to variouscomponents including the network board 200, via one or morecommunications isolators 160. The DSP 150 may also provide controlsignals to one or more boost converters 162A, 162B, and 162C, which maybe used to regulate electricity supplied to the corresponding LEDmodules 400A-400C via ports 104A-104C. The boost converters 162A-162Cmay receive DC power directly once converted from AC power via therectifier 157. The DSP 150 may receive power from the bias and controlpower supply 156, a voltage and current measurement from the AC linesensor 155, and thermal sensor inputs via the thermal sensor ports 154,which may be used to monitor the temperature of the LED modules400A-400C.

The network board 200 may be used to manage data communication betweenthe lighting fixture 1000 and various devices coupled to the lightingfixture 1000 including, but not limited to other lighting fixtures 1000and one or more auxiliary sensors coupled to the lighting fixture 1000.As shown in FIG. 11A, in some implementations, the network board 200 maycontrol one or more PoE ports 1008A, 1008B, 1008C, and 1008D of thelighting fixture 1000. The network board 200 may receive electricalpower and control signals from the control board 100 via a control boardport 102. The network board 200 may also supply electrical power andcontrol signals to the single board computer 300 via a single boardcomputer port 202. The network board 200 may also support a dedicatedEthernet cable connection 212 through an Ethernet port 213 between thenetwork board 200 and the single board computer 300 to manage datatransfer through the PoE ports 1008A-1008D.

A more detailed block diagram of the network board 200 in FIG. 11A isshown in FIG. 11C. The control board port 102 may be used to supplyelectrical power at different voltages, e.g., 48 V and 5 V, to a PoEcontroller 206, a power supply 208, and a fan controller and port 210.The control board port 102 may also directly relay control signals fromthe control board 100 to the single board computer 300 via the singleboard computer port 202. In some implementations, the control board port102 may be arranged as a piggyback board to the network board 200. ThePoE controller 206 may be used to regulate and supply electrical powerto the PoE ports 1008A-1008D. The power supply 208 may supply electricalpower to the single board computer 300, through the single boardcomputer port 202, and to an Ethernet switch 204. The Ethernet switch204 is communicatively coupled to the PoE ports 1008A-1008D and to thesingle board computer 300 via the Ethernet port 213, which supports thededicated Ethernet cable connection 212. The Ethernet switch 204 may beused to facilitate receipt and transmission of data and/or controlsignals to and from the PoE ports 1008A-1008D.

The single board computer 300 may provide several functions to theprocessor 90 including, but not limited to managing the operation of thecontrol board 100 and the network board 200 and data processing. Asshown in FIG. 11A, the single board computer 300 may also be used tosupport the functionality of USB ports 1012A and 1012B on the lightingfixture 1000. The single board computer 300 may include a memory card350 that contains (has stored thereon) various data and computerexecutable code 352 including, but not limited to, session bordercontroller (SBC) software, an operating system, web server software andother web server assets.

The processor 90 may be used to manage the voltage and current suppliedto various components of the lighting fixture 1000, e.g., a power cable,the LED modules 400A-400C, in order to reduce the likelihood of damageunder different operating conditions. For example, the lighting fixture1000 may be operated under low voltage conditions where 1200 W may besupplied to the LED modules 400A-400C and 65 W for auxiliary sensors.The power cable used to supply electricity to the lighting fixture 1000from an external source, e.g., a building electrical supply system, maybe rated to sustain a current up to 15 A. The processor 90 may be usedto limit the current through the lighting fixture 1000 to 5 A such thatthree lighting fixtures 400A-400C may be powered by a single power cable1030. If the current draw of the lighting fixture 1000 approaches 5 A,the processor 90 may reduce the power draw of the lighting fixture. Inthis manner, the three lighting fixtures 400A-400C may collectivelyavoid a total current draw that exceeds 15 A, thus reducing thelikelihood of damaging the power cable.

In some implementations, the processor 90 may enforce a current drawlimit using an active feedback control loop. For instance, the DSP 150of the control board 100 may be used to actively measure the voltage andcurrent supplied to the lighting fixture 1000 via the AC line sensor155. Depending on the magnitude and/or rate of change of the measuredvoltage and current, the DSP 150 may then adjust the voltage and currentsupplied to each of the LED modules 400A-400C such that the currentdrawn by the lighting fixture 1000 is maintained below the current drawlimit. This process may be conducted in an iterative manner wheremeasurements of the voltage and current supplied to the lighting fixture1000 and subsequent adjustments to the voltage and current supplied tothe LED modules 400A-400C repeatedly occur at a preset timescale. Thetimescale may vary from about 1 ms to about 60 s. The amount the voltageand current are varied during each increment may also vary according tothe rate of change of the voltage and current supplied to the lightingfixture 1000. In some implementations, the stability of the activefeedback control loop may be controlled by incorporating a proportionalintegral differential (PID) controller into the processor 90.

FIGS. 12A-12D, 13, 14A-14H show circuit diagrams of various electricalcomponents of a processor 90 according to one implementation. FIG. 12Ashows a circuit diagram of an Ethernet switch 204 from a network board200 and the electrical connections to PoE ports 1008A-1008D and anEthernet port 213 for communication to a single board computer 300. FIG.12A also shows a circuit diagram of a power supply 208 from the networkboard 200. For visual clarity, FIGS. 12B and 12C show expanded views ofthe Ethernet switch 204 and the PoE port 1008D from FIG. 12A,respectively. FIG. 12D shows a circuit diagram of a PoE controller 206from the network board 200. FIG. 13 shows a circuit diagram of a singleboard computer 300 detailing various input and output connections. FIG.14A shows circuit diagrams for an electrical power port 1010, fuse/EMIfilter 153, a rectifier 154, and a first portion of a bias and controlpower supply 156 from a control board 100. FIG. 14B shows a secondportion of the bias and control power supply 156 shown in FIG. 14A.FIGS. 14C-14F show a DC-DC converter 158, an AC line sensor 155, a DSP150, and thermal sensor ports 154 from the control board 100. FIGS. 14Gand 14H show circuit diagrams of an exemplary boost circuit 162A fromthe control board 100.

The lighting fixture 1000 disclosed herein may also be utilized in aleased lighting system where a customer pays a recurring fee to rent andoperate the lighting fixture 1000 (e.g., provide lighting using thelighting fixture 1000). In this system, the costs typically associatedwith purchasing the lighting fixture 1000 hardware and installation maybe substantially reduced, thus providing substantial savings to thecustomer. The manufacturer providing the operation of the lightingfixture 1000 may earn a profit over time through continuing payments bythe customer. In some implementations, the leased lighting system may bebased on payment of a fee to operate the lighting fixture 1000 for apreset period of time. The lighting fixture 1000 may be communicativelycoupled to a server via the processor 90. The server may remotelyregulate operation of the lighting fixture, enabling the lightingfixture 1000 to provide lighting so long as the customer providesnecessary payment to maintain the lease.

An exemplary implementation of a contract enforcement method where thelighting fixture 1000 is communicatively coupled to a license server 600is shown in FIG. 15A. As shown, the license server 600 may include adatabase 602 containing information including, but not limited to aserial number for one or more lighting fixtures 1000 installed by acustomer and a customer status (e.g., a payment status) for the customerto which the one or more lighting fixtures 1000 are leased. The databasemay also include a pre-shared key 604, which is also installed onto eachlighting fixture 1000, e.g., such as in protected internal storage ofthe DSP 150 of the lighting fixture 1000, by the manufacturer, togetherwith a timer, prior to shipment to the customer. Upon initial payment bythe customer, the manufacturer may setup an initial timer update in thedatabase 1000 to provide for some time period for initial lighting,after which an additional lease payment is required. Once the lightingfixture 1000 is deployed to the customer, the expiration of the timermay trigger a license update process. Once the additional lease paymentis made, the manufacturer operating the license server 600 may updatethe database 602 with a new timer value, which is communicated to thelighting fixture 1000. Communication may occur via a proprietarycommunication protocol.

An exemplary implementation of a process to update a license for aleased lighting model with one or more lighting fixtures 1000 is shownin FIG. 15B. In this exemplary process, the DSP 150 and the single boardcomputer 300 of the processor 90 may be coupled to the license server600 and database 602 via the Internet to facilitate operation by themanufacturer of the one or more lighting fixtures 1000 or a leasingagent. As described above, the pre-shared key 604 and license timer maybe stored in the protected internal storage of the DSP 150 by themanufacturer together with the serial number of the lighting fixture1000. The single board computer 300 may periodically check the status ofthe license timer. Once the license timer is near expiration, the singleboard computer 300 may initiate with the DSP 150 a license updaterequest. This request may include a “challenge packet” generated by theDSP 150, which is forwarded by the single board computer 300 to thelicense server 600. The challenge packet may include encryptedinformation based, at least in part, on the serial number of thelighting fixture 1000 and a temporary random key generated using a noiseaccumulator. The challenge packet may then be decrypted by the licenseserver 600. If the challenge packet is found to be valid and payment ismade for additional lighting, the license server 600 may then determinea new allowed timer value. The new allowed timer value may then beencrypted and sent back to the single board computer 300, which passesthe encrypted timer value to the DSP 150. The DSP 150 may then decryptthe new timer value based on the pre-shared key 604. If the new timervalue is found to be valid, the DSP 150 may update the license timerstored in the protected internal storage of the DSP 150.

CONCLUSION

While various inventive implementations have been described andillustrated herein, those of ordinary skill in the art will readilyenvision a variety of other means and/or structures for performing thefunction and/or obtaining the results and/or one or more of theadvantages described herein, and each of such variations and/ormodifications is deemed to be within the scope of the inventiveimplementations described herein. More generally, those skilled in theart will readily appreciate that all parameters and configurationsdescribed herein are meant to be exemplary inventive features and thatother equivalents to the specific inventive implementations describedherein may be realized. It is, therefore, to be understood that theforegoing implementations are presented by way of example and that,within the scope of the appended claims and equivalents thereto,inventive implementations may be practiced otherwise than asspecifically described and claimed. Inventive implementations of thepresent disclosure are directed to each individual feature, system,article, and/or method described herein. In addition, any combination oftwo or more such features, systems, articles, and/or methods, if suchfeatures, systems, articles, and/or methods are not mutuallyinconsistent, is included within the inventive scope of the presentdisclosure.

The above-described implementations can be implemented in multiple ways.For example, implementations may be implemented using hardware, softwareor a combination thereof. When implemented in software, the softwarecode can be executed on any suitable processor or collection ofprocessors, whether provided in a single computer or distributed amongmultiple computers. Further, it should be appreciated that a computermay be embodied in any of a number of forms, such as a rack-mountedcomputer, a desktop computer, a laptop computer, or a tablet computer.Additionally, a computer may be embedded in a device not generallyregarded as a computer but with suitable processing capabilities,including a Personal Digital Assistant (PDA), a smart phone or any othersuitable portable or fixed electronic device.

Also, a computer may have one or more input and output devices. Thesedevices can be used, among other things, to present a user interface.Examples of output devices that can be used to provide a user interfaceinclude printers or display screens for visual presentation of outputand speakers or other sound generating devices for audible presentationof output. Examples of input devices that can be used for a userinterface include keyboards, and pointing devices, such as mice, touchpads, and digitizing tablets. As another example, a computer may receiveinput information through speech recognition or in other audible format.Such computers may be interconnected by one or more networks such asInternet. The various methods or processes outlined herein may be codedas software that is executable on one or more processors that employ anyone of a variety of operating systems or platforms. Additionally, suchsoftware may be written using any of a number of suitable programminglanguages and/or programming or scripting tools, and also may becompiled as executable machine language code or intermediate code thatis executed on a framework or virtual machine.

In this respect, various inventive concepts may be embodied as acomputer readable memory or storage medium (or multiple computerreadable storage media) (e.g., a computer memory, one or more floppydiscs, compact discs, optical discs, magnetic tapes, flash memories,circuit configurations in Field Programmable Gate Arrays or othersemiconductor devices, or other non-transitory medium or tangiblecomputer storage medium) encoded with one or more programs that, whenexecuted on one or more computers or other processors, perform methodsthat implement the various implementations of the invention discussedabove. The computer readable medium or media can be transportable, suchthat the program or programs stored thereon can be loaded onto one ormore different computers or other processors to implement variousaspects of the present invention as discussed above.

Unless otherwise indicated, the terms “program” or “software” are usedherein in a generic sense to refer to any type of computer code or setof computer-executable instructions that can be employed to program acomputer or other processor to implement various aspects ofimplementations as discussed above. Additionally, it should beappreciated that according to one aspect, one or more computer programsthat when executed perform methods of the present invention need notreside on a single computer or processor, but may be distributed in amodular fashion amongst a number of different computers or processors toimplement various aspects of the present invention.

Computer-executable instructions may be in many forms, such as programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. Typically, the functionality of the program modulesmay be combined or distributed as desired in various implementations.

Also, data structures may be stored in computer-readable media in anysuitable form. For simplicity of illustration, data structures may beshown to have fields that are related through location in the datastructure. Such relationships may likewise be achieved by assigningstorage for the fields with locations in a computer-readable medium thatconvey relationship between the fields. However, any suitable mechanismmay be used to establish a relationship between information in fields ofa data structure, including through the use of pointers, tags or othermechanisms that establish relationship between data elements. In someimplementations, a schema-minimal storage system may be implemented in arelational database environment using key-value storage versus defineddata structures.

Also, various inventive concepts may be embodied as one or more methods,of which an example has been provided. The acts performed as part of themethod may be ordered in any suitable way. Accordingly, implementationsmay be constructed in which acts are performed in an order differentthan illustrated, which may include performing some acts simultaneously,even though shown as sequential acts in illustrative implementations.

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one implementation, to A only (optionally including elements otherthan B); in another implementation, to B only (optionally includingelements other than A); in yet another implementation, to both A and B(optionally including other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of.” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one implementation, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another implementation, to at least one, optionallyincluding more than one, B, with no A present (and optionally includingelements other than A); in yet another implementation, to at least one,optionally including more than one, A, and at least one, optionallyincluding more than one, B (and optionally including other elements);etc.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively, as set forth in the United States Patent Office Manual ofPatent Examining Procedures, Section 2111.03.

1. A lighting fixture, comprising: an extruded aluminum housing; atleast one light source mechanically supported by the extruded aluminumhousing; and at least one copper pipe thermally coupled to the extrudedaluminum housing to carry a fluid coolant, wherein: the at least onelight source includes at least one LED light source; during operation ofthe lighting fixture the fluid coolant flowing through the at least onecopper pipe extracts heat generated by the lighting fixture; and thefluid coolant does not contact the extruded aluminum housing.
 2. Thelighting fixture of claim 1, wherein the lighting fixture does notinclude any internal seals for the fluid coolant.
 3. The lightingfixture of claim 1, wherein the lighting fixture does not include anyinternal O-rings for the fluid coolant.
 4. The lighting fixture of claim1, wherein: the extruded aluminum housing includes at least one cavityto contain control circuitry to control the at least one light source;and the lighting fixture does not include any seals for the fluidcoolant or O-rings for the fluid coolant within the at least one cavityof the extruded aluminum housing.
 5. The lighting fixture of claim 1,wherein: the extruded aluminum housing includes at least one channelformed therein; and the at least one copper pipe is press-fit into theat least one channel of the extruded aluminum housing so as to establisha thermal connection between the at least one copper pipe and theextruded aluminum housing.
 6. The lighting fixture of claim 1, wherein:the at least one copper pipe includes a first copper pipe and a secondcopper pipe both thermally coupled to the extruded aluminum housing tocarry the fluid coolant.
 7. The lighting fixture of claim 6, wherein:the first copper pipe and the second copper pipe carry the fluid coolantin a coolant circuit when the fluid coolant is present, such that thefluid coolant flows in different directions respectively through thefirst copper pipe and the second copper pipe.
 8. The lighting fixture ofclaim 1, wherein the extruded aluminum housing includes a light spine tofacilitate mechanical coupling of the lighting fixture to at least onesupport structure of a controlled agricultural environment.
 9. Thelighting fixture of claim 1, further comprising at least one port toprovide auxiliary DC power to at least one auxiliary device coupled tothe at least one port.
 10. The lighting fixture of claim 9, wherein theat least one port provides the auxiliary DC power and data coupling forthe at least one auxiliary device coupled to the at least one port. 11.The lighting fixture of claim 9, wherein the at least one port comprisesat least one of: at least one Power over Ethernet (PoE) port tofacilitate power coupling and data coupling of at least one firstexternal device to the lighting fixture; or at least one UniversalSerial Bus (USB) port to facilitate coupling of at least one secondexternal device to the lighting fixture.
 12. A system, comprising: atleast one lighting fixture according to claim 9; and at least one sensorcoupled to the at least one port.
 13. The system of claim 12, whereinthe at least one sensor includes at least one of: an air temperaturesensor; a near infrared (NIR) sensor; a relative humidity sensor; acamera; a carbon dioxide (CO2) sensor; or an infrared (IR) sensor.
 14. Acontrolled agricultural environment, comprising: the system of claim 12;at least one cooling tower; and at least one fluid circuit coupled tothe at least one cooling tower and the at least one copper pipe of theat least one lighting fixture to carry the fluid coolant between the atleast one cooling tower and the at least one lighting fixture.
 15. Thecontrolled agricultural environment of claim 14, further comprising adehumidifier.
 16. The controlled agricultural environment of claim 15,wherein the dehumidifier is coupled to the at least one fluid circuit.17. The controlled agricultural environment of claim 14, furthercomprising at least one fan.
 18. The controlled agricultural environmentof claim 17, wherein: the at least one lighting fixture includes a fancontroller; and the at least one fan is communicatively coupled to thefan controller of the at least one lighting fixture.
 19. The controlledagricultural environment of claim 18, wherein the at least one fan iscoupled to the at least one port of the at least one lighting fixture.20. The controlled agricultural environment of claim 14, wherein thecontrolled agricultural environment does not include an air conditionercomprising an air conditioning condenser, an air conditioningcompressor, and/or an air conditioning coil.
 21. The controlledagricultural environment of claim 14, further comprising: a buildingstructure in which the system is disposed; at least one supportstructure arranged in the building structure for supporting the system,wherein the at least one lighting fixture is mechanically coupled to theat least one support structure; and at least one shelving structure tosupport a plurality of plants, the at least one shelving structurearranged in the building structure with respect to the at least onesupport structure to facilitate irradiation of the plurality of plantsby photosynthetically active radiation (PAR) provided by the at leastone lighting fixture.
 22. A controlled agricultural environment,comprising: a building structure to house a plurality of plants; and atleast one fluid-cooled LED-based lighting fixture disposed in thebuilding structure to provide photosynthetically active radiation (PAR)to the plurality of plants, wherein the controlled agriculturalenvironment does not include an air conditioner comprising an airconditioning condenser, an air conditioning compressor, and/or an airconditioning coil.
 23. The controlled agricultural environment of claim22, wherein: the at least one fluid-cooled LED-based lighting fixtureincludes: a plurality of Power over Ethernet (PoE) ports to facilitatepower coupling and data coupling of at least one first external deviceto the lighting fixture; and at least one Universal Serial Bus (USB)port to facilitate coupling of at least one second external device tothe lighting fixture; and the environment further comprises at least onesensor coupled to at least one of the plurality of PoE ports or the atleast one USB port of the at least one lighting fixture.
 24. Thecontrolled agricultural environment of claim 23, wherein the at leastone sensor includes at least one of: an air temperature sensor; a nearinfrared (NIR) sensor; a relative humidity sensor; a camera; a carbondioxide (CO2) sensor; or an infrared (IR) sensor.
 25. The controlledagricultural environment of claim 22, wherein: the at least onefluid-cooled LED-based lighting fixture includes a plurality offluid-cooled LED-based lighting fixtures; each lighting fixture of theplurality of fluid-cooled LED-based lighting fixture comprises: anextruded aluminum housing; and at least one copper pipe thermallycoupled to the extruded aluminum housing to carry a fluid coolant.
 26. Amethod for controlling an agricultural environment, the methodcomprising: A) irradiating a plurality of plants with photosyntheticallyactive radiation (PAR) output by at least one fluid-cooled lightingfixture; B) flowing a fluid coolant through at least one fluid circuitin the agricultural environment to substantially remove excess heat inthe agricultural environment, wherein the at least one fluid circuitincludes the at least one fluid-cooled lighting fixture; C) sensing atleast one condition in the agricultural environment; and D) controllingat least one of the PAR output by the at least one fluid-cooled lightingfixture and a flow of the fluid coolant based at least in part on the atleast one sensed condition in C).
 27. The method of claim 26, whereinthe environment does not include an air conditioner comprising an airconditioning condenser, an air conditioning compressor, and/or an airconditioning coil.
 28. The method of claim 26, wherein: the agriculturalenvironment includes at least one dehumidifier; and the excess heatcomprises at least one of: lighting heat generated by the at least onelighting fixture; plant heat generated by the plurality of plants; anddehumidifier heat generated by the at least one dehumidifier.
 29. Themethod of claim 26, wherein C) comprises sensing the at least onecondition using at least one of: an air temperature sensor; a nearinfrared (NIR) sensor; a relative humidity sensor; a camera; a carbondioxide (CO2) sensor; or an infrared (IR) sensor.
 30. A fluid-cooledlighting fixture, comprising: a housing; at least one light sourcedisposed in or on the housing; and a copper fluid coolant circuitthermally coupled to the housing to contain a fluid coolant that, whenpresent in the coolant circuit, extracts heat generated by the at leastone light source during operation of the lighting fixture, wherein thelighting fixture does not contain any internal seals or internal O-ringsfor the fluid coolant.